Conventionally, as an electromagnetic relay, there is one wherein an iron core 4 is inserted into a through-hole in a body portion of a coil bobbin 1 around which a coil 2 is wounded, and a tip end portion 4a that protrudes is inserted through an opening 5a of a yoke 5 having a generally L-shape in cross section to be caulked and fixed (refer to Patent Document 1).    Patent Document 1: JP4-272628A